Drive apparatus and method for its operation

Abstract

A drive apparatus with at least one synchronous motor, a converter and a mechanical energy buffer able to be fed from an energy supply network, which, for converting mechanical energy into electrical current, includes a first asynchronous machine, and a method of operation for such a drive apparatus are specified, with which or in which the energy buffer, especially its first asynchronous machine is directly electrically connected via a switchover device to the at least one synchronous motor, so that the converter included in the drive apparatus is bypassed for such a switch position of the switchover device and the converter accordingly does not have to be designed for currents which flow in such a switch position of the switchover device.

1. A drive apparatus for converting a mechanical energy into an electrical current, comprising:
 an energy supply network; 
 a mechanical energy buffer connected to the energy supply network; 
 a converter connected to the mechanical energy buffer; 
 a switchover device comprising a first input directly connected to the mechanical energy buffer and a second input connected to the converter; 
 a first synchronous motor connected to the switchover device; and 
 a first asynchronous machine that is electrically directly connected to the first synchronous motor via the switchover device, 
 wherein the first synchronous motor is electrically directly connected to the first asynchronous machine via the switchover device, and 
 wherein a second synchronous motor is fed directly from the energy supply network via the converter. 
 
     
     
       2. The drive apparatus as claimed in  claim 1 ,
 wherein the first synchronous motor is electrically directly connected to the first asynchronous machine via the switchover device, and 
 wherein the second synchronous motor is electrically connected to the first synchronous motor via the converter. 
 
     
     
       3. The drive apparatus as claimed in  claim 1 ,
 wherein the first synchronous motor is electrically directly connected to the first asynchronous machine via the switchover device, and 
 wherein the second synchronous motor is fed directly from the energy supply network via the converter and an electrical energy buffer. 
 
     
     
       4. The drive apparatus as claimed in  claim 1 , further comprising a control device. 
     
     
       5. The drive apparatus as claimed in  claim 4 , wherein the control device controls the switchover device to electrically directly connect the first synchronous motor to the first asynchronous machine during a first operating state. 
     
     
       6. The drive apparatus as claimed in  claim 5 , wherein the control device controls the switchover device to electrically connect the first synchronous motor to the first asynchronous machine via the converter during a second operating state. 
     
     
       7. The drive apparatus as claimed in  claim 6 , wherein the switchover device disconnects the direct electrical connection between the first synchronous motor and the first asynchronous machine during the second operating state. 
     
     
       8. The drive apparatus as claimed in  claim 6 ,
 wherein the first operating state comprises an operating state with an essentially constant speed and a high power demand, and 
 wherein the second operating state comprises an operating state with a variable speed and a lower power demand than the first operating state. 
 
     
     
       9. The drive apparatus as claimed in  claim 8 , wherein the converter is power rated for the second operating state. 
     
     
       10. The drive apparatus as claimed in  claim 1 , wherein the mechanical energy buffer comprises:
 a flywheel that is mechanically connected to the first asynchronous machine, and 
 a second asynchronous machine that is connected to the energy supply network. 
 
     
     
       11. A method for operating a drive apparatus, comprising:
 providing an energy supply network; 
 connecting the energy supply network to a mechanical energy buffer; 
 connecting the mechanical energy buffer to a converter; 
 providing a switchover device comprising a first input directly connected to the mechanical energy buffer and a second input connected to the converter; 
 connecting the switchover device to a first synchronous motor; and 
 controlling the switchover device for electrically directly connecting the first synchronous motor to a first asynchronous machine, 
 wherein the first synchronous motor is electrically directly connected to the first asynchronous machine via the switchover device, and 
 wherein a second synchronous motor is fed directly from the energy supply network via the converter. 
 
     
     
       12. The method as claimed in  claim 11 , wherein the switchover device is controlled by a control device. 
     
     
       13. The method as claimed in  claim 12 , wherein the control device controls the switchover device to electrically directly connect the first synchronous motor to the first asynchronous machine during a first operating state. 
     
     
       14. The method as claimed in  claim 13 , wherein the control device controls the switchover device to electrically connect the first synchronous motor to the first asynchronous machine via the converter during a second operating state. 
     
     
       15. The method as claimed in  claim 14 , wherein the control device determines whether an operating state is the first operating state or the second operating state and controls the switchover device accordingly. 
     
     
       16. The method as claimed in  claim 15 , wherein the control device comprises a program code for implementing the method.